#welcome{
    position: relative;
    .bg{
        width: 100vw;
        height: 100vh;
         background: #fff!important;
    }
   .box{
       position: absolute;
       top: 0;
       left: 0;
       width: 100vw;
       height: 100vh;
       z-index: 10000;
       .head{
            img{
                margin-left: 60vw;
                width: 35vw;
                margin-top:3vh;
            } 
       }
       .top{
           img{
                margin-left: 25vw;
                width: 55vw;
                margin-top:3vh;
           }
       }
       .middle{
           img{
                margin-left: 28vw;
                width: 50vw;
                margin-top:3vh;
           }
       }
       .bottom{
            button{
                width:100px;
                height:36px;
                display: block;
                margin: 0 auto;
                border: none;
                background: transparent;
                margin-top:5vh;
                background:url(../img/welcome/btn.png);
                background-size:100% 100% ;
                background-repeat:no-repeat;
                background-position: 0 0;
            }
        }
    }
}
@media screen and (min-width: 500px) {
    #welcome{
        position: relative;
        .bg{
            width: 100vw;
            height: 100vh;
            background: #fff!important;
        }
        .box{
            position: absolute;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            z-index: 10000;
            .head{
                img{
                    margin-left: 70vw;
                    width: 26vw;
                    margin-top:3vh;
                } 
            }
            .top{
                img{
                    margin-left: 30vw;
                    width: 45vw;
                    margin-top:3vh;
                }
            }
            .middle{
                img{
                    margin-left: 35vw;
                    width: 40vw;
                    margin-top:3vh;
                }
            }
            .bottom{
                button{
                    width:120px;
                    height:40px;
                    display: block;
                    margin: 0 auto;
                    border: none;
                    background: transparent;
                    margin-top:5vh;
                    background:url(../img/welcome/btn.png);
                    background-size:100% 100% ;
                    background-repeat:no-repeat;
                    background-position: 0 0;
                }
            }
        }
    }
}